President Donald Trump has called for a dramatic reordering of America's priorities in his first budget, with "less money on people overseas and more money on people at home".

The budget plan boosts the country's military spending and funds Mr Trump's "border wall" with Mexico, but guts resources for aid, foreign diplomacy and the environment.

Calling it the "America First" plan, Mr Trump's $1.1trn (€1trn) proposal is designed to strike fear in the hearts of US enemies, while making good on his election pledge to "drain the swamp" of government bureaucracy in Washington.

"We are absolutely reducing funding to the UN and various other foreign aid budgets," said Mick Mulvaney, the White House's budget director.

He said the Trump administration was cutting spending for climate-change efforts because "we consider that to be a waste of your money".

The plan increases military spending by $54bn - a full 10pc. And it allocates $2.8bn to the department of homeland security, which will largely go towards paying for a wall along the border with Mexico and hiring 500 more border patrol guards. Mr Trump has always insisted Mexico will eventually pay for the wall.

"The president very clearly wants to send a message to our allies and our potential adversaries that this is strong power administration," Mr Mulvaney said.

Overall, however, the budget calls for the most sizeable drawdown of government-funded programmes since the Second World War, slashing assistance to the poor, the funding of scientific research and foreign aid.

It takes an axe to America's foreign diplomatic service, proposing to reduce the size of the state department by 28pc.

Secretary of state Rex Tillerson defended the cuts as a necessary correction to a "historically high" budget for the department that had grown to address conflicts abroad and provide foreign aid.

But Mr Trump's swingeing cuts to the budget for diplomacy were met with dismay at the United Nations, where the US is the largest financier. One diplomat described the US "retreat" from global affairs as "a recipe for disaster", while Francois Delattre, France's ambassador to the UN, said yesterday that they hoped their "US friends" would realise massive cuts to the UN's budget would not help their stated aim of achieving security.

The fight against terrorism, migration issues and climate change all posed serious threats, he said, which were fought through the UN.

"In today's testing times, when we are confronted with an unprecedented accumulation of crisis, we need a strong UN more than ever," he said.

"America's retreat and unilateralism - or even the perception of it by other players - would create the risk of going back to the old spheres of influence policy. And history teaches us the dangers of that."

Hardest hit from the domestic programmes is the Environmental Protection Agency, which would lose almost one-third of its resources.

Mr Trump, a sceptic of man-made climate change, wants to get rid of more than 50 of its programmes, including revoking funding for programmes aimed at reducing carbon dioxide emissions.

The budget also proposes totally eliminating government support for the National Endowment for the Arts, and other groups that fund public television and radio stations and support artists and writers.